Astin scored a career defining, triumphant success in the inspirational and universally applauded college football biopic Rudy (1993), about the life-changing struggles and rewards of the title character, Daniel Ruettiger. He followed his success in Rudy by starring in films throughout the 1990s, including the Showtime science fiction film Harrison Bergeron (1995), the Gulf War film Courage Under Fire (1996), the Warren Beatty political satire Bulworth (1996) and the romantic comedy Boy Meets Girl (1997).
In the early 2000s, Astin experienced another career breakthrough with his role as Samwise Gamgee in Peter Jackson's The Lord of the Rings film trilogy, released in 2001, 2002 and 2003. Along with the many awards bestowed upon the trilogy, particularly its final installment The Return of the King (winner of eleven Academy Awards, including Best Picture), Astin received many award nominations for his own performance in Return of the King, taking home the Saturn Award for Best Supporting Actor and awards from the Las Vegas Film Critics Society, the Seattle Film Critics, the Utah Film Critics Association, and the Phoenix Film Critics Society. As an ensemble, the Return of the King cast received awards from the National Board of Review of Motion Pictures and the Screen Actors Guild.
Since Lord of the Rings, Astin has consistently worked in film and television. His film roles have included the Adam Sandler comedies 50 First Dates (2004) and Click. More recently, Astin appeared in the second season of Netflix’s popular series Stranger Things in which he played the role of Bob Newby.